RE: Oracle and NAS storage systems

AFAIK, the downside of RAID4 is the same as RAID5. Writes to the disk must
calculate parity data which impacts performance. Also, the parity disks tend
to be the hotspots on these arrays. Any writes must also write data to the
parity disk.

I took a one week course in NetApp filers a while ago. I was impressed by
their products, but not as database storage. They are a great solution if
you are using a heterogeneous environment of CIFS and NFS. The ability to
'snapshot' the file system was also very cool and I used this as a way of
performing QUICK hot backups.

Erik

> -----Original Message-----> From: DENNIS WILLIAMS [SMTP:DWILLIAMS_at_LIFETOUCH.COM]> Sent: Monday, July 15, 2002 12:49 PM> To: Multiple recipients of list ORACLE-L> Subject: RE: Oracle and NAS storage systems> > Erik - Very interesting, thanks for mentioning that fact. Of course, since> there's "no free lunch", what is the downside to RAID4?> > Dennis Williams> DBA> Lifetouch, Inc.> dwilliams_at_lifetouch.com> > -----Original Message-----> Sent: Monday, July 15, 2002 11:23 AM> To: Multiple recipients of list ORACLE-L> > > I think that NA uses RAID4. This is the same as RAID5, but the parity info> is not stripped across the disks. This allows them to add disks from the> spare spool very quickly, as parity info does not need to be recalculated.> Spare disks are simply 'zeroed-out' prior to use. > > > -----Original Message-----> > From: DENNIS WILLIAMS [SMTP:DWILLIAMS_at_LIFETOUCH.COM]> > Sent: Monday, July 15, 2002 11:58 AM> > To: Multiple recipients of list ORACLE-L> > Subject: RE: Oracle and NAS storage systems> > > > Dick - > > We use NetAppliance to store Oracle datafiles on our test system. I> am> > pretty sure the NetAppliance is configured as RAID5. I would rate it as> > quite satisfactory for that purpose. We have many test systems and they> > are> > only used sporadically. > > I have had no reliability issues with the NetAppliance, so I can't> > figure> > what EMC means by it being "risky".> > I did find that if performance is pushed to a high level, the> > NetAppliance seems to have problems. I can't say for sure whether the> > problem is with the NetAppliance or with a network bottleneck. For> > example,> > I was going to rebuild 5 or 6 large indexes. Both the table and the> index> > were on the NetAppliance system. I started a script to simultaneously> > build> > these indexes and went home for the night. Based on my experience with> our> > normal RAID5 drives, I came in the next morning fully expecting all> those> > indexes to be built. None of the indexes got rebuilt. My guess is that> > there> > was too much contention. I built the indexes one at a time, moving the> > base> > table to a normal RAID5, and performance was quite satisfactory. Have> had> > no> > further problems or test user complaints.> > I wouldn't commit to using NAS on a system that will push the disk> > drive> > subsystem really hard. Maybe for a less-critical system that needs> access> > to> > large amounts of cheap disk. Test first. I have also heard of a lot of> SAN> > systems being mis-configured and producing poor or erratic database> > performance.> > > > Dennis Williams> > DBA> > Lifetouch, Inc.> > dwilliams_at_lifetouch.com> > > > -----Original Message-----> > Sent: Monday, July 15, 2002 9:43 AM> > To: Multiple recipients of list ORACLE-L> > > > > > Folks,> > > > I've been asked to validate/invalidate a contention made by two> > storage> > vendors. > > > > NetAppliance has stated that you can use a netapp filer with Oracle> > for> > datafiles, although their configuration looks more like a DAS(direct> > attached> > storage) configuration using 10baseT cables vs. SCSI cables. Of course> > their> > real claim to fame here is Oracle's endorsement.> > > > EMC on the other hand has stated that using a NAS, in the> traditional> > mode,> > for Oracle datafiles is at best risky. And although their product can> > support> > it, they do not recommend doing so for several of the reasons that I've> > held> > out> > are pertinent.> > > > Therefore, is there anyone out their using a NAS to store datafiles?> > If> > so,> > what does the configuration (server to NAS) look like?> > > > Dick Goulet> > -- > > Please see the official ORACLE-L FAQ: http://www.orafaq.com> > -- > > Author: > > INET: dgoulet_at_vicr.com> > > > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051> > San Diego, California -- Public Internet access / Mailing Lists> > --------------------------------------------------------------------> > To REMOVE yourself from this mailing list, send an E-Mail message> > to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in> > the message BODY, include a line containing: UNSUB ORACLE-L> > (or the name of mailing list you want to be removed from). You may> > also send the HELP command for other information (like subscribing).> > -- > > Please see the official ORACLE-L FAQ: http://www.orafaq.com> > -- > > Author: DENNIS WILLIAMS> > INET: DWILLIAMS_at_LIFETOUCH.COM> > > > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051> > San Diego, California -- Public Internet access / Mailing Lists> > --------------------------------------------------------------------> > To REMOVE yourself from this mailing list, send an E-Mail message> > to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in> > the message BODY, include a line containing: UNSUB ORACLE-L> > (or the name of mailing list you want to be removed from). You may> > also send the HELP command for other information (like subscribing).> > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com> -- > Author: Erik Williams> INET: ewilliams_at_brownco.com> > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051> San Diego, California -- Public Internet access / Mailing Lists> --------------------------------------------------------------------> To REMOVE yourself from this mailing list, send an E-Mail message> to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in> the message BODY, include a line containing: UNSUB ORACLE-L> (or the name of mailing list you want to be removed from). You may> also send the HELP command for other information (like subscribing).> -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com> -- > Author: DENNIS WILLIAMS> INET: DWILLIAMS_at_LIFETOUCH.COM> > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051> San Diego, California -- Public Internet access / Mailing Lists> --------------------------------------------------------------------> To REMOVE yourself from this mailing list, send an E-Mail message> to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in> the message BODY, include a line containing: UNSUB ORACLE-L> (or the name of mailing list you want to be removed from). You may> also send the HELP command for other information (like subscribing).

--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Erik Williams
INET: ewilliams_at_brownco.com
Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
San Diego, California -- Public Internet access / Mailing Lists
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